Over-travel and return mechanism for door

ABSTRACT

The specification and drawings disclose a plug-type door assembly particularly suited for use on rail cars. The door assembly includes the usual door member carried on vertically extending shaft and crank assemblies provided with rollers on which the door can be moved longitudinally of a door opening. Actuating means are provided for selectively rotating the crank assemblies to cause the door to move into and out of the opening. The actuating means are of the type having both anti-overspin and anti-drift characteristics. Located adjacent the door opening is a cushion member which is adapted to absorb the kinetic energy of the door. Means including a lost motion connection and a spring are associated with the crank assemblies for permitting inward movement of the leading edge portion of the door toward the cushion member when a stop member engages the crank assembly. After engagement with the cushion member, the spring assembly returns the door to a full open position.

United States Patent 1 Ross, Jr. et al.

OVER-TRAVEL AND RETURN MECHANISM FOR DOOR Inventors: Irving D. Ross,Jr.; Thorvald Madland, both of Barrington, Ill.

The Youngstown Steel Doon Company, Cleveland, Ohio Feb. 8, 1971Assignee:

Filed:

' Appl. No.: 113,143

References Cited UNITED STATES PATENTS 4/1917 Copony 2/1970 Herr 8/196749/220 Landis et a1. 49/220 July 24, 1973 Primary Examiner-KennethDowney Attorney-Fay, Sharpe & Mulholland [57] ABSTRACT v Thespecification and drawings disclose a plug-type.

door assembly particularly suited for use on rail cars. The doorassembly includes the usual door member carried on vertically extendingshaft and crank assemblies provided with rollers on which the door canbe moved longitudinally of a door opening. Actuating means are providedfor selectively rotating the crank assemblies to cause the door to moveinto and out of the opening. The actuating means are of the type havingboth anti-overspin and anti-drift characteristics. Located adjacent thedoor opening is a cushion member which is adapted to absorb the kineticenergy of the door. Means including a lost motion connection and aspring are associated with the crank assemblies for permitting inwardmovement of the leading edge portion of the door toward the cushionmember when a stop member engages the crank assembly. After engagementwith the cushion member, the spring assembly returns the door to a fullopen position.

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4 TTOENE 75 OVER-TRAVEL AND RETURN MECHANISM FOR DOOR The presentinvention is directed toward the rail car art and, more particularly, toan improved return and shock cushioning arrangement for plug-type doors.

Plug-type rail car doors are in wide use and generally comprise arelatively heavy door assembly carried on vertical pipes or shafts. Thepipes are provided at their opposite ends with crank arms and rollers.The rollers ride on tracks extending along the side of the car and allowthe door to move longitudinally to and from the door opening. When thedoor is positioned in front of the door opening, rotation of the shaftscauses the door to be moved into and out of the opening.

In the commonly assigned co-pending application, Ser. No. 50,288, filedJune 26, 1970, for Dual Brake Type Drive Mechanism, we have disclosed amechanism which overcomes two particular problems when used as anoperating mechanism for plug-type doors. First, the mechanism preventsoverspinning (acceleration of the manual operating handle out of controlof the operator by forces acting on the door) and drifting (inadvertentmovement of the door toward andaway from the car when in the openposition).

An additional problem which is present in plug-type doors involvesstopping the door at the end of movement along the longitudinal tracks.As can be appreciated, the door has substantial mass and is difficult tostop without substantial impact on the door and its drive mechanism.Although it has been proposed that shock absorbing door stops orcushions be provided, the problem has been that in order to engage theedge of the door in its open position, the stops had to extend laterallyof the car a substantial distance. This was generally unacceptable.

The present invention provides a mechanism which overcomes the aboveproblem and is especially suited for use on plug-type doors having bothanti-drift and anti-overspin actuating mechanisms of the type describedin the aforementioned patent application. The inventive mechanism isarranged to direct the door inwardly toward a cushion member at the endof its travel so that the doors kinetic energy is absorbed by thecushion without damage to the door, the crank assemblies, or the drivemechanism. The arrangement is such that the cushion member or members donot have to extend outwardly of the car any appreciable distance. Also,no impactforces can be transmitted through the guide wheels-or rollersto the drive mechanism and the mechanism functions to return the door toa full open position (i.e., the position ithad immediately prior tomoving inwardly toward the cushion).

In accordance with one aspect of the invention, an improvement isprovided for a plug-type rail car door ofthe general type including adoor member carried on vertically extending shaft and crank assembliesincluding roller means to allow the door to move laterally into and outof a door opening in the side of a car, as well as, to movelongitudinally of the car in first and second directions. Theimprovement comprises door actuating means for selectively rotating thecrank members to cause the door to move into and out of the opening.

Preferably, but not necessarily, the actuating means include means forselectively maintaining the door in a position outwardly of the openingduring longitudinal movement. Associated with the door are stop meansarranged to engage at least one of the assemblies when the door ismoving in the first direction, and over-travel means for permittingmovement of at least the leading edge portion of the door toward the carupon engagement of the shaft and crank assembly with the stop means.

Preferably, and in accordance with an aspect of the invention, a cushionmeans is located to engage the leading edge portion of the door when itmoves inwardly toward the car and thereby absorb the kinetic energy ofthe door. The over-travel means further includes spring means to returnthe door to its full open position or the position it had immediatelyprior to engagement with the stop means.

Accordingly, a primary object of the invention is the provision of adoor operating mechanism of the general type described wherein the dooris stopped in the m'anner described without damage and automaticallyreturned to the position it had prior to being stopped.

A further object is the provision of a plug door assembly arranged suchthat the kinetic energy of the moving door is absorbed by a cushion orstop member spaced inwardly of the doors open position.

A further object is the provision of a plug door assembly of the typedescribed which is relatively simple and which prevents any undue impactforces from acting against the door operating mechanism.

These and other objects and advantages will become apparent from thefollowing description when read in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a front elevation of a plug-type rail car shown incorporatinga preferred embodiment of the invention and showing the door in a closedposition;

FIG. 2' is a cross-sectional view taken on line 2-2 showing the door inthe closed position;

FIG. 3 is a cross-sectional view taken on line 2-2 of FIG. 1 but showingthe door in an open position imme diately prior to closing;

FIG. 4 is an enlarged cross-sectional view taken on line 4-4 of FIG. 1but showing the door in an open position immediately prior to closing;

FIG. 5 is an enlarged cross-sectional view taken on line 4-4 of FIG. 1but showing the position of the door as it impacts the shock absorbingcushion;

FIG. 6 is an enlarged elevation showing the return spring mechanism indetail;

FIG. 7 is a cross-sectional view taken on line 7-7 of FIG. 6 showing thedoor operating clevis when the door is in the closed position;

FIG. 8 is a cross-sectional view taken on line 77 of FIG. 6 but showingthe clevis in the open position; and

FIG. 9 is a cross-sectional view taken on line 99 of FIG. 4.

Referring more particularly to FIGS. 1 and 2, there is shown a railroadcar indicated generally by the reference numeral 10 and having a sideopening 12 in which is positioned a plug-type door assembly 14. The doorassembly 14 is provided with an opening and closing mechanism indicatedgenerally by the reference numeral l8.

The structural details of the railroad car 10 and the general structuraldetails of door 12 are not ofparticular importance to the invention;however, the door 12 is shown as formed from a pair of spaced,vertically extending frame members 20 and 22 each having thecross-section best shown in FIGS. 2 and 3. The members 20 and 22 arejoined by somewhat similar, horizontally extending frame members 23through 26. Connected to the back of the frame members, such as bywelding, is a rectangular section of sheet metal 28 that closes thespaces between the door frame members and provides a rigid doorstructure.

As is customary with plug-type doors, the assembly 14 is mounted so thatit can be moved laterally into and out of the opening 12 and, when inthe open position, moved longitudinally of the car 10. As illustrated inFIG. 1, the door assembly 14 is carried on a pair of verticallyextending pipe or shaft members 30, 32. At the lower end of each of theshafts 30, 32 are laterally extending lever arms 34. A roller hangerassembly 36 is pivotally mounted at the outer ends of each of the cranksor arms 34. Similarly, at the upper ends of shafts 30, 32, arms 38 areconnected and extend laterally outward as shown. At the outer ends ofeach of the arms 38 there are provided guide rollers 40 which extendvertically upward for rotation about respective vertical axes. Theroller hanger assemblies 36 are each carried for movement on a tracksection 42 mounted longitudinally on the outer surface of the car. Theupper guide rollers 40 are positioned for movement in a downwardly openguideway 44 which also extends longitudinally of the car.

As is apparent, rotation of the left and right shaft and crankassemblies in the clockwise and counterclockwise directions,respectively, cause the door to be swung outwardly away from the car,whereas, rotation in the opposite directions moves the door intoengagement with the opening 12. As best shown in FIG. 2, a compressiongasket or seal member 46 is preferably positioned about the peripheraledge of the door so that when the door is moved into the closedposition, the gasket engages the inwardly extending flanges on the dooropening to seal the door.

In the embodiment under consideration, means are provided for lockingthe door in its closed position. These means could take many forms butare illustrated by horizontally slidable lock bolt members 50. Each ofthe lock bolt members is carried by a pair of brackets 52 connected tothe vertically extending door frame members 20, 22. The uppermost pairof lock bolt members 50 is driven by horizontally extending drive bars54. Similarly, the lower set of lock bolts are arranged for drivingmovement by a horizontally extending pair of drive bars 56.

As best seen in FIG. 2, the ends of the lock bolt members 50 engage withgenerally cup-shaped keeper members 58 carried in the door opening 12.Preferably, and in accordance with the subject embodiment, the verticalpipes 30, 32 and the horizontally extending lock bolt members 50 are alldriven from a common opening and closing mechanism 18. Mechanism 18 ismanually operable from an exterior handle or crank member 60. The driveassembly 18 is shown and described in detail in commonly assignedco-pending U. S. Pat. application, Ser. No. 50,288, filed June 26, 1970,for Dual Brake Type Drive Mechanism which is incorporated herein byreference. The assembly is arranged to prevent overspinning and driftingof the door. That is, when the door is in the process of being opened,the drive assembly functions to prevent outwardly acting forces on thedoor from causing the actuating handle to be driven out of control ofthe operator. This sometimes happens with prior plug door operatingmechanisms when bulk contents such as grain and the like are beinghandled. Similarly, the mechanism is arranged so that when the door isin the open position, it cannot inadvertently drift back inwardlyagainst the side of the car. That is, the mechanism locks the crank armsin their open position.

The actuating mechanism described in the aforementioned patentapplication solves two of the major problems with plug-type doors. Anadditional, previously mentioned problem present in plug-type doorsresides in the movement of the door along the track and stopping of thedoor adjacent the opening. As can be appreciated, the door hassubstantial mass and must be stopped during longitudinal movementwithout damage to the door or its support and actuating mechanisms. Thishas been accomplished by various types of track stops and bumperarrangements. If the door is suddenly stopped by a fixed track mountedstop member which engages the wheels or roller hanger assemblies 36,substantial jarring of the wheels takes place which can damage thewheels and, also, the drive mechanism. Alternatively, if a bumper memberor the like is arranged for engagement by the edge of the door, thebumper must extend outwardly an undue distance laterally of the car.Thus, when the door is closed for car travel, the bumper presents anobjectionable extension of the car.

In the subject invention, the above problem is overcome by a uniquecrank assembly over-travel mechanism which is designed so that as thedoor moves toward a predetermined stop position, engagement of the shaftand crank assemblies with a stop member permits the leading edge of thedoor to swing inwardly to engage an inwardly mounted cushion or stopmember and, thereafter, to return outwardly to the full open position ithad prior to engagement with the stop. The mechanism is arranged so thatno loads are transmitted to the drive mechanism and both the overspinand antidrift functions of the operating mechanism are retained.

The preferred form of the over-travel mechanism is as best shown inFIGS. 4 through 9. Referring in particular to FIG. 6, the vertical pipeor shaft 30 is pivotally mounted at its lower end by a bracket 62 orotherwise connected to the U-shaped frame members 23. A torsion springmember 64 is positioned about the lower end of shaft 30 at a locationimmediately above the top surface of the frame member 23. One end of thespring 64 is connected to a spring retainer 66 comprised of a plate 68and upwardly extending pin 70. The opposite end of the spring 64 isconnected to a small spring flange or lever arm 72 rigidly connected tothe pipe 30 such as by welding. It will be noted that a rivet or thelike 74 passes through the end of the spring and is welded to the flangeor lever arm 72.

In certain instances, the return spring would not be required sincenormal rebound from the energy absorbing cushion would return the doorand crank and shaft assemblies to the position assumed prior toengagement with the stop. However, the use of the spring is muchpreferred since it assures that the door will always return to the fullopen position even when it is moving very slowly when it impacts thestop.

FIGS. 4, 5, and 7 through 9 illustrate the operation of the mechanismbetween the door opened and door closed positions. As best shown inFIGS. 2 and 7, when the door is in the closed position, the shaftoperating crank -.or clevis 76 makes an angle of approximately 30degrees relative to a plane perpendicular to the door panel face 78. Itwill be noted that crank 76 is drivingly connected to the door operatingmechanism 18 by a rod 80 which is connected to the clevis 76 by a pin82. For reasons which will hereafter be discussed, the rod 80 has anelongated pin receiving slot 84. When the door is in the closed positionillustrated in FIG. 5, the torsion spring 64 is in a no-torque position.That is, the spring is relaxed and under no load or slight reverse load.When the door operating mechanism is actuated to move the door to theopen position, the operating clevis 76 is rotated to the position shownby solid lines in FIGS. 3, 4 and 8. During the rotation of the clevis,the'pipe 30 (also pipe 32) is rotated to pivot the lower crank arms 34causing the door to move laterally out of the opening to the positionshown in FIG. 3. During this opening movement, the spring 64 is slightlytorqued". A stop 65 (see FIG. 1) is carried on actuating rod 80 toengage the drive housing 81 to provide a positive indication that thedoor is fully open. It will be noted that the lower crank arm 34 is thusat a position perpendicular to the face of the door. The door isoutwardly spaced on the side of the car and can freely move up and downthe tracks 42, 44.

When it is desired to close the door, it is rolled to the left towardthe door opening to the position shown in FIG. 2. Positioned on track 42adjacent the opening is a stop member 88. It will be noted that the stopmember 88 is arranged to engage the left roller trolley assembly 36 at aposition adjacent the door opening.As shown, the stop preferablyincludes a portion which extends upwardly over the trolley assembly toprevent the assembly from lifting when it engages the stop. As can beappreciated, because of the mass of the door and the possibility of thedoor moving rapidly, substantial jarring could take place against thewheel trolleys and the drive mechanism if the door were completelystopped by engagement with the wheel trolleys. In the subject device,the over-travel mechanism functions to direct the leading edge of thedoor inwardly against an inwardly spaced resilient bumper stop 89 andthereafter, return the door to the position it had prior to engagementwith the stop. Additionally, the mechanism prevents undue forces frombeing applied to the wheel carriage or the drive mechanism. Although astop is shown only on the lower track 42, a stop could also be used onthe upper track or guideway 44. In certain instances, this would bedesirable.

As will best be seen in FIG. 4, engagement of the wheel carriage 36 withthe stop 88 causes the wheel trolley 36 to positively stop at thelocation shown. The door, however, continues to move to the left andpivots the crank 34 and the clevis 76 to the position shown in FIG. 5.The right hand shaft 32 and trolley assembly 36 do not pivot butcontinue moving with the door. This causes the doors leading edge 12 toswing inwardly toward the side of the car. As the leading edge pivotsinwardly, it comes into engagement with the resilient bumper or stop 89thus absorbing and dissipating the kinetic energy in the door. Duringthe final pivoting movement, i.e., the movement from the position shownin FIG. 4 to the position shown in FIG. 5, the return spring 64 isfurther torqued. (FIG. 8 shows the movement of crank 76 during thisperiod.) Thus, after engagement with the cushion, the return springcauses the door and the crank to be returned to the solid line positionin FIG. 6. It will be noted that the elongated slot 84 acts as a lostmotion connection to permit the inward movement and prevents any loadfrom being ap plied to the actuating rod during movements between thenormal door open and cushion engaging positions. When the elements haveassumed the solid line positions in FIGS. 8 and 9, normal actuating ofthe manual operating mechanism can be carried out to close the door intoengagement with the opening.

An additional feature which should be noted is the presence of a camplate member 90 carried on the actuating clevis 76. The cam acts duringthe last part of the action. Note that as the rod 80 is moved from theposition of FIG. 7 to the position of FIG. 8, the cam engages thelateral surface of the rod head to provide a final camming actionoperation to eliminate the lost motion during closure.

As is readily apparent, the described mechanism allows the door to bepivoted inwardly against an inwardly positioned stop and does notinterfere with the functioning of the anti-drift mechanism. Thus, theantidrift mechanism is fully operative throughout all movements of thedoor while allowing limited desired movements to absorb the impact ofthe door closing operation and also, a final positioning of themechanism.

The invention has been described in great detail sufficient to enableone of ordinary skill in the door art to make and use the same.Obviously, modifications and alterations of the preferred embodimentwill occur upon a reading and understanding of the specification and itis our intention to include allsuch modifications andalterations as partof our invention insofar as they come within the scope of the appendedclaims.

What is claimed is: l. A plug-type rail car door assembly comprising: adoor member; at least a pair of shaft and crank assemblies supportingsaid door on roller means for permitting said door assembly to be movedin a first direction longitudinally toward a door opening and in asecond direction longitudinally away from a door opening,

said assemblies having cranks mounted to be rotated through an arcdefined by a first door closed position and a second door open positionwherein said cranks are substantially normal to said door and a thirdposition beyond said second position from said first position,

actuating means for rotating said shaft and crank assemblies to causesaid door member to move out of and into said door opening as saidcranks are moved respectively from said first position to said secondposition and from said second position to said first position,

said actuating means including means maintaining the cranks of saidassemblies in said second position during longitudinal movement of saiddoor on said roller means, 1

stop means for engaging said roller means to stop said roller means at apredetermined point relative to said opening during longitudinalmovement of said door in said first direction;

cushion means adjacent said opening and inwardly of the edges of thedoor when said cranks are in said second position;

over-travel means including spring means connected between said door andcrank assembly,

whereby upon engagement of said roller means with said stop means theedge of the door in the direction of travel pivots inwardly, relative toits position 3. The improvement as described in claim 2 wherein saidover-travel means includes a lost motion connection between said rod andclevis and a coil spring member positioned about a portion of said shaftand crank assembly and connected between said door and said shaft andcrank assembly.

4. The improvement as described in claim 3 including means operative toindicate proper pre-torquing of the spring means when the door is in theopen position.

1. A plug-type rail car door assembly comprising: a door member; atleast a pair of shaft and crank assemblies supporting said door onroller means for permitting said door assembly to be moved in a firstdirection longitudinally toward a door opening and in a second directionlongitudinally away from a door opening, said assemblies having cranksmounted to be rotated through an arc defined by a first door closedposition and a second door open position wherein said cranks aresubstantially normal to said door and a third position beyond saidsecond position from said first position, actuating means for rotatingsaid shaft and crank assemblies to cause said door member to move out ofand into said door opening as said cranks are moved respectively fromsaid first position to said second position and from said secondposition to said first position, said actuating means including meansmaintaining the cranks of said assemblies in said second position duringlongitudinal movement of said door on said roller means, stop means forengaging said roller means to stop said roller means at a predeterminedpoint relative to said opening during longitudinal movement of said doorin said first direction; cushion means adjacent said opening andinwardly of the edges of the door when said cranks are in said secondposition; over-travel means including spring means connected betweensaid door and crank assembly, whereby upon engagement of said rollermeans with said stop means the edge of the door in the direction oftravel pivots inwardly, relative to its position during longitudinalmovement, toward said cushion means to absorb the kinetic energy in thedoor as the cranks move from their second position to their thirdposition and by action of the spring means back to the second position.2. The invention as described in claim 1 wherein said actuating meansincludes a rod pivotally attached to a clevis rigidly mounted on saidshaft means for selectively maintaining said door in a positionoutwardly of said door opening during longitudinal movement.
 3. Theimprovement as described in claim 2 wherein said over-travel meansincludes a lost motion connection between said rod and clevis and a coilspring member positioned about a portion of said shaft and crankassembly and connected between said door and said shaft and crankassembly.
 4. The improvement as described in claim 3 including meansoperative to indicate proper pre-torquing of the spring means when thedoor is in the open position.